This invention relates to improvement in disc brakes of the kind in which friction pads are adapted to be urged by hydraulic acting means into engagement with opposite faces of a rotatable friction disc and more particularly to fluid pressure operated disc brakes of the kind having a stationary member adapted to be secured to a non-rotatable part of a wheel assembly, a movable member movable on the stationary member, fluid pressure operated brake actuating means incorporated into the movable member, a brake pad or pads on one side of the friction disc slidably guided by the stationary member and directly responsive to the fluid pressure operated brake actuating means, and a second friction pad or pads on the opposite side of the friction disc, the reaction force derived from contact with the brake disc of the pad or pads directly responsive the brake actuating means resulting in movement of the movable member to bring the second pad or pads on the opposite side of the brake disc into contact therewith.
It has been the practice in conventional brakes of this kind that the movable member is directly sliding fit on the stationary member. In order to attain ease of installation in such sliding fit, tolerance is substantially limited to a very slight one in the manufacture of such parts. This is considered to be a disadvantage in the manufacturing costs and for convenience in installation of the brake. Further, there exists normally the possibility of corroding with rust in such direct sliding fit, owing to water, moisture or humidity. It has been proven to be a fact in the art that corrosion is apt to be exhibited particularly where two or more different steel parts are in contact relation under moisture condition.
While various means have been previously employed for avoiding the above mentioned disadvantage and defect, none have proven, in our view point, satisfactory.